Effect of Three Pregermination Treatments on the Growth of Emerging Seedlings of Acacia auriculiformis (Cunn. Ex. Benth)

This research was carried out to determine the effect of some pregermination treatments on the seeds of Acacia auriculiformis as it affects growth. The treatments involve the effect of sulphuric acid (concentration and time), mechanical scarification (at different sides), and hot water treatment (volume and time). Split plot design was used for acid treatment and hot water treatment, while Randomized Complete Block Design (RCBD) was used for mechanical scarification. The experiment was carried out at Federal University of Agriculture, Abeokuta, Nigeria. Parameters assessed include; plant height, stem height, leaf number. Acid treatment was carried out using different concentration of sulphuric acid (98%, 50% and 20%) and different treatment time (2 minutes, 5 minutes and 10 minutes). Concentration of acid was significant (p<0.05) on plant height, stem height and leaf number, higher concentration of acid (98%) enhanced morphological parameters of Acacia auriculiformis. Result showed that mechanical scarification significantly affect stem height (p<0.05), however, while mechanical scarification does not significantly affect plant height, the highest mean plant height (8.98 cm) was observed in seeds that were mechanically scarified at the micropyle; early germination of seeds was also noticed. Hot water treatment was carried out using different volume of water (50 cl and 1 litre) and varying treatment time (2 minutes, 4 minutes, 6 minutes and 10 minutes), the treatment showed no significant difference, and this method is not favourable for breaking seed dormancy of Acacia auriculiformis. Result showed that 100% germination could be achieved within seven (7) days when seeds are mechanically scarified at the micropyle, circumference, distal-end and micropyle+distalend, provided the seeds are viable. This research conclude that, acid scarification using H2SO4 at 98% concentration is the best method yielding better morphological parameters in Acacia auriculiformis, followed by mechanical scarification (especially when scarified at the micropyle).